The PX100s were the second decent portable headphone I bought after the KSC75s, a silky-smooth contrast to the shiny, aggressive sound of the Koss clip-ons. This particular review was written when I was very new to the world of Head-Fi but in general I stand by it.

Build Quality: Designed to be portable, the PX100s fold beautifully into a tiny package and fit into the included plastic carrying case. Despite the multi-jointed folding mechanism, they feel rather solid and sturdy. The metal headband is both tough and flexible and there’s a feel of quality to the whole construction – every motion they make feels controlled one as the joints click smoothly into place. I expected them to be quite fragile at first, but there are no creaks or rattles after two years of use.

Comfort: The rotating earcups adjust perfectly to the shape of your head, preventing uneven pressure on your ears, which can be a problem with the other supraaural phones. The foam pads are a little thicker than the stock KSC75 pads and feel slightly smoother. The padding on the headband looks miniscule but gets the job done without making your head sweat. I’ve worn these for 6-8 hour stretches on several occasions with no adverse effects.

Isolation: The PX100s are open phones. They let outside noise in and leak sound out. Though not as drastically open as, for example, Grados, they are still pretty useless as far as isolation goes.

Sound: The PX100s are dark, warm, laid back, and very, very smooth. The vocals are nowhere near as forthcoming as the KSC75s and they are missing the treble sparkle. They do, however, have bass that is tighter and better controlled than both the KSC75s and PortaPro, causing them to sound more accurate on trance and techno tracks (though they are still quite bloated compared to higher-end portables). They don’t really work as well as I would like with my preferred genres, which are rock and metal, because of laid-back nature and dark tone but to be quite honest I still reach for these very often over the KSC75s though I prefer the Koss sound signature in general.

Value. (MSRP: $59.99, Street Price: $35) The PX100s are very good headphones. I would recommend them at the $35 price point any day. It is a matter of preference, however, whether these are better than KSC75 and PortaPros, On a very tight budget, I would go with the KSC75s. However, with price out of consideration, I would probably take these even over the PortaPros as relaxed all-rounders. It should be noted that fake PX100s have popped up on ebay on occasion, so I’d be wary of anything that doesn’t come in retail packaging and with the carrying case.